1. Field of the Invention
The present invention relates to a fundus imaging apparatus and a control method.
2. Description of the Related Art
In order to capture a suitable fundus image using a fundus camera, it is necessary to focus on the fundus of each eye individually. This is because different eyes to be examined have different degrees of refraction. A fundus camera having an autofocus function has been proposed as a camera designed to facilitate such a focusing operation. In general, when imaging the fundus of an eye, such a fundus camera performs focusing by using a focus lens placed in an observation optical system and focus indices which are driven in synchronism with the focus lens.
In this case, if a diopter correction lens for correcting strong myopia or hyperopia is inserted in the observation optical system, the optical relationship between split and focus changes. That is, if a diopter correction lens is inserted in the observation optical system, since the optical relationship between the focus lens and the focus indices deteriorates, it is impossible to perform focusing by using the focus indices. This makes it necessary for the examiner to manually perform focusing while observing an actual fundus image. Japanese Patent Laid-Open No. 2011-189063 has disclosed an invention which facilitates manual focusing operation by changing the operation sensitivity of a focus lens when a diopter correction lens is inserted.
It is however cumbersome for the examiner to perform such a manual focusing operation. The lower the degree of skill of the examiner, the more time it takes for the focusing operation. This imposes a burden on the person having their eye examined and may cause stress to the eye itself.